The invention relates to an apparatus for mixing and a method of mixing propellant charge powder rods.
It is conventional to produce propellant charge powders in individual batches. To a certain extent the properties of the propellant charge powder vary from batch to batch because the manufacturing conditions prevailing during production of a batch are not precisely reproducible for another batch. Therefore, different batches of any one type of powder are mixed together in order to minimize the spread of the propellant charge powder characteristics around a given medium value, thus obtaining uniform quality in the long run.
Where the propellant charge powder is available in the form of sticks or rods, the mixing so far is carried out manually, with strict observance of mixing rules, for example by exchanging certain proportions of batches of propellant charge powder rods positioned side by side on a mixing table. Although attempts have been made in the past to mechanize the mixing process by the use of mixing drums, they did not meet with success since the propellant charge powder rods assumed oblique positions in the mixing drum, becoming jammed with one another, and impeding the further movement of the rods so that mixing no longer took place. Another disadvantage of the mixing drum method became evident in emptying the mixing drums: Prior to being able to pass on the unaligned, crisscross heap of rods to further steps in the production, they had to be fed to a vibrating or sorting device for proper alignment.
It is the object of the instant invention to indicate an apparatus and a method by which to mix propellant charge powder rods mechanically.